Fuel Filter Change on a 98 4.3l vortec 4x4
CanukGMC
03-26-2006, 06:00 PM
Hey all, I just changed the fuel filter in my 98 and it was a real PITA. More so than I expected. I tried searching here but didn't find much info. I thought I'd post some of my "findings" to help others who decide to do their spring tune up. BTW this quick guide will work for most Jimmy's as far as I know, there's only 1 difference, pre96\97 jimmys had a fuel filter with flare nuts on EITHER side, after late 96's and up they came with a quick connect on the front and a flare nut on the back.
1)The fuel filter is located inboard of the drivers side frame rail pretty much underneath where the drivers seat is. The very UNfortunate part about this location is that it is directly behind the torsion bar. For some of us this isn't a big deal, I'm 6'5" 290 lbs with gorrila hands so for me this was a very big deal lol.
http://img132.imageshack.us/img132/4641/fuelfilter98jimmy0028mk.jpg
2)The shraeder valve can be poked to remove some of the pressure on the lines (stops fuel from spraying you in the face). See picture below. The top unscrews like a valve stem on a tire. Put paper towels around and under it and use a stick\screwdriver\whatever to poke the middle (just like letting air out of a tire) and gas will spray out. Hold it until the fuel stops coming out. Done.
http://img132.imageshack.us/img132/6442/fuelfilter98jimmy0031dq.jpg
3)HERE'S SOME GOOD INFO TO SAVE YOU ALOT OF HASSLE. I have a very extensive socket collection, I am limited on my wrenches (lost a whole box in a move, grrr) these days. The flare nut on the hard steel line is a 16mm metric nut. The bracing nut on the fuel filter itself is a 20mm nut. THIS IS VERY IMPORTANT. Get your fingers and wrenches in there and break the flare nut loose (put a wrench on each nut and turn oppositely). It's time consuming but start undoing the flare nut until it begins leaking fuel. I put a catch bucket under it to catch the fuel, it will stop dripping eventually.
4)Now for the "quick connect" on the engine side of the filter. There are 2 plastic prongs near the base of the connector, squeeze them with needle nose and pull the line off, it should come off easily IF you squeeze the prongs in far enough. The new filter will come with new "prongs" for the new filter, don't loose them, snap them on before putting the filter in there.
5)Getting the old filter out is a big pain, if you notice it has a plastic ring around it holding it in place. Chiltons didn't mention this one to me. It was by far the longest part of my day. Up above the filter there is a bolt (13mm) that holds this whole plastic do-hickey to the frame. The bolt comes out easy enough, but that's the the first part. I found I could get one hand over the frame between the body to the top of the plastic peice and one hand from underneath and I could move it around that way. But above where it bolts to the fram is a series of 3 "runners". The brake lines and return fuel lines run through these "tracks" in the plastic which are all part of the plastic ring holding the fuel filter in there.
IN A PERFECT WORLD, the lines will snap out of the grooves\tracks\runners\whatever, and the whole plastic peice and filter will come out as one. This however did not happen. No matter what I did I could -not- get those lines out of the runners. I tried even prying them but they are HARD steel lines and any bending will result in a break\crack and now you have a big job at hand. I also tried pushing the filter out of the ring it was in so I could just slide in a new one, wrong, it wouldn't budge at all. I tried for about 45mins to get it out of that damned thing before I gave up, bent it over to get at it and managed to cut through the plastic enough to seperate the filter from the top half where the lines snapped in.
4)To maneuver the filter out I had to slide it down along the fram rail and out a slot in the skid plate under the transfer case, it's easy enough to do. Once out I still had the plastic ring around the filter, this was only removed after bracing the filter and pounding a wrench onto the plastic much like a "caveman bearing press". I then pressed the new filter into the ring using a bit of grease and raw angry power. It fits SO TIGHTLY that the little bumps on the ring actually left grooves on the filters body!
5)I then, since I cut the ring from the main body of the plastic mount thing, re-bolted the plastic mount to the frame (sans filter) so the hard lines were braced. Then I drilled 2 holes in the ring itself (it had a peice coming straight up off of it where it used to be attached to the other half of it under the truck. Through those holes I ran 2 zip ties, I put the filter back in the same way the old one came out, zip tied it to the rest of it's plastic peice\hard lines so it wouldn't move, re-attached the hard line and flare nut (this again is as slow as it came off) and snapped the quick connect line on.
6)Turn the ignition key forward, let it sit for a second, then turn it off, then forward again (the point where the gauges light up and the stereo comes on) and repeat about 5 times to pressurize the system and purge the air from the filter. Start her up and check for leaks.
I don't recommend you "cut" the plastic mount thing if you can avoid it, I only beat a dead horse so long before I risk further damaging other things and give up and "make up" my own way of doing it. I hope at least some of this info might help someone else looking at doing this in the future. Fuel filters are one of the simplest ways to keep a fuel pump strong, this should be a very simple and easy project, for some reason mine turned into almost an hour and a half lol. :)
1)The fuel filter is located inboard of the drivers side frame rail pretty much underneath where the drivers seat is. The very UNfortunate part about this location is that it is directly behind the torsion bar. For some of us this isn't a big deal, I'm 6'5" 290 lbs with gorrila hands so for me this was a very big deal lol.
http://img132.imageshack.us/img132/4641/fuelfilter98jimmy0028mk.jpg
2)The shraeder valve can be poked to remove some of the pressure on the lines (stops fuel from spraying you in the face). See picture below. The top unscrews like a valve stem on a tire. Put paper towels around and under it and use a stick\screwdriver\whatever to poke the middle (just like letting air out of a tire) and gas will spray out. Hold it until the fuel stops coming out. Done.
http://img132.imageshack.us/img132/6442/fuelfilter98jimmy0031dq.jpg
3)HERE'S SOME GOOD INFO TO SAVE YOU ALOT OF HASSLE. I have a very extensive socket collection, I am limited on my wrenches (lost a whole box in a move, grrr) these days. The flare nut on the hard steel line is a 16mm metric nut. The bracing nut on the fuel filter itself is a 20mm nut. THIS IS VERY IMPORTANT. Get your fingers and wrenches in there and break the flare nut loose (put a wrench on each nut and turn oppositely). It's time consuming but start undoing the flare nut until it begins leaking fuel. I put a catch bucket under it to catch the fuel, it will stop dripping eventually.
4)Now for the "quick connect" on the engine side of the filter. There are 2 plastic prongs near the base of the connector, squeeze them with needle nose and pull the line off, it should come off easily IF you squeeze the prongs in far enough. The new filter will come with new "prongs" for the new filter, don't loose them, snap them on before putting the filter in there.
5)Getting the old filter out is a big pain, if you notice it has a plastic ring around it holding it in place. Chiltons didn't mention this one to me. It was by far the longest part of my day. Up above the filter there is a bolt (13mm) that holds this whole plastic do-hickey to the frame. The bolt comes out easy enough, but that's the the first part. I found I could get one hand over the frame between the body to the top of the plastic peice and one hand from underneath and I could move it around that way. But above where it bolts to the fram is a series of 3 "runners". The brake lines and return fuel lines run through these "tracks" in the plastic which are all part of the plastic ring holding the fuel filter in there.
IN A PERFECT WORLD, the lines will snap out of the grooves\tracks\runners\whatever, and the whole plastic peice and filter will come out as one. This however did not happen. No matter what I did I could -not- get those lines out of the runners. I tried even prying them but they are HARD steel lines and any bending will result in a break\crack and now you have a big job at hand. I also tried pushing the filter out of the ring it was in so I could just slide in a new one, wrong, it wouldn't budge at all. I tried for about 45mins to get it out of that damned thing before I gave up, bent it over to get at it and managed to cut through the plastic enough to seperate the filter from the top half where the lines snapped in.
4)To maneuver the filter out I had to slide it down along the fram rail and out a slot in the skid plate under the transfer case, it's easy enough to do. Once out I still had the plastic ring around the filter, this was only removed after bracing the filter and pounding a wrench onto the plastic much like a "caveman bearing press". I then pressed the new filter into the ring using a bit of grease and raw angry power. It fits SO TIGHTLY that the little bumps on the ring actually left grooves on the filters body!
5)I then, since I cut the ring from the main body of the plastic mount thing, re-bolted the plastic mount to the frame (sans filter) so the hard lines were braced. Then I drilled 2 holes in the ring itself (it had a peice coming straight up off of it where it used to be attached to the other half of it under the truck. Through those holes I ran 2 zip ties, I put the filter back in the same way the old one came out, zip tied it to the rest of it's plastic peice\hard lines so it wouldn't move, re-attached the hard line and flare nut (this again is as slow as it came off) and snapped the quick connect line on.
6)Turn the ignition key forward, let it sit for a second, then turn it off, then forward again (the point where the gauges light up and the stereo comes on) and repeat about 5 times to pressurize the system and purge the air from the filter. Start her up and check for leaks.
I don't recommend you "cut" the plastic mount thing if you can avoid it, I only beat a dead horse so long before I risk further damaging other things and give up and "make up" my own way of doing it. I hope at least some of this info might help someone else looking at doing this in the future. Fuel filters are one of the simplest ways to keep a fuel pump strong, this should be a very simple and easy project, for some reason mine turned into almost an hour and a half lol. :)
CanukGMC
03-26-2006, 08:27 PM
I took my truck for a drive to checkit out after I gave the throttle body a good cleaning with some spray cleaner. I can see a difference already (from the tbod cleaning and the fuel filter), it's quite impressive. Not only does the truck accelerate smoother but the very faint miss it had at idle is gone, the fuel pump doesn't have this weird "whine" it used to (probably because the old filter was finished, a ton of silt and black crap came out the back of it when I removed it). I'm glad I got this done, now onto the spark plugs, yikes damned intermediate shaft!
ChrisGood
03-27-2006, 11:57 AM
The plugs are not too bad just remove the shroud in the wheel wells and turn the wheels hard to either side and you can get right up in there. I put the socket on the plug then went below and attached to it and it only took about 10 minutes a plug and a dictionary of cursing... But it wasnt so bad I would take other items apart to get a better reach. As for the Fuel Filter, I had a horrible time with those lines, I was able to get them to pop off and help me skin my knuckles at the same time, but even with the filter and black holster out of the car it took some major convincing to get the filter out. I put a little vaseline on the new one in hopes of making the next replacement a little easier.
CanukGMC
03-27-2006, 02:05 PM
The plugs are not too bad just remove the shroud in the wheel wells and turn the wheels hard to either side and you can get right up in there. I put the socket on the plug then went below and attached to it and it only took about 10 minutes a plug and a dictionary of cursing... But it wasnt so bad I would take other items apart to get a better reach. As for the Fuel Filter, I had a horrible time with those lines, I was able to get them to pop off and help me skin my knuckles at the same time, but even with the filter and black holster out of the car it took some major convincing to get the filter out. I put a little vaseline on the new one in hopes of making the next replacement a little easier.
"Major convincing" is an understatement lol. I looked at the plugs today and decided to let them be for a while, they look like a nightmare. The passengers side plugs are severely covered too since half the AC system runs over that way, I'm having trouble just tracing the plug wires to the plugs themselves. It's quite a job, I want to pull the intermediate shaft since I need to inspect it anyways (loose steering) but get this. To get to the shaft I need to remove the aircleaner box, to remove the air cleaner box I need to disconnect rad hoses, and even then I can't seem to find out how the air cleaner attaches to the front gill. Argh it's just so packed in there. I'll figure it out soon enough I'm sure lol.
"Major convincing" is an understatement lol. I looked at the plugs today and decided to let them be for a while, they look like a nightmare. The passengers side plugs are severely covered too since half the AC system runs over that way, I'm having trouble just tracing the plug wires to the plugs themselves. It's quite a job, I want to pull the intermediate shaft since I need to inspect it anyways (loose steering) but get this. To get to the shaft I need to remove the aircleaner box, to remove the air cleaner box I need to disconnect rad hoses, and even then I can't seem to find out how the air cleaner attaches to the front gill. Argh it's just so packed in there. I'll figure it out soon enough I'm sure lol.
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